1. Field of the Invention
This invention pertains to multi-panel ballistic resistant articles including both flexible and semi-rigid panel components. Each panel of the multi-panel ballistic resistant articles may include either woven or non-woven fibrous layers, or both. Semi-rigid panels are molded under varying pressures to achieve varying degrees of stiffness.
2. Description of the Related Art
Ballistic resistant articles containing high strength fibers that have excellent properties against projectiles are well known. Articles such as bullet resistant vests, helmets, vehicle panels and structural members of military equipment are typically made from fabrics comprising high strength fibers. High strength fibers conventionally used include polyethylene fibers, aramid fibers such as poly(phenylenediamine terephthalamide), graphite fibers, nylon fibers, glass fibers and the like. For many applications, such as vests or parts of vests, the fibers may be used in a woven or knitted fabric. For other applications, the fibers may be encapsulated or embedded in a matrix material to form non-woven rigid or flexible fabrics.
Various ballistic resistant constructions are known that are useful for the formation of hard or soft armor articles such as helmets, panels and vests. For example, U.S. Pat. Nos. 4,403,012, 4,457,985, 4,613,535, 4,623,574, 4,650,710, 4,737,402, 4,748,064, 5,552,208, 5,587,230, 6,642,159, 6,841,492, 6,846,758, all of which are incorporated herein by reference, describe ballistic resistant composites which include high strength fibers made from materials such as extended chain ultra-high molecular weight polyethylene. These composites display varying degrees of resistance to penetration by high speed impact from projectiles such as bullets, shells, shrapnel and the like.
For example, U.S. Pat. Nos. 4,623,574 and 4,748,064 disclose simple composite structures comprising high strength fibers embedded in an elastomeric matrix. U.S. Pat. No. 4,650,710 discloses a flexible article of manufacture comprising a plurality of flexible layers comprised of high strength, extended chain polyolefin (ECP) fibers. The fibers of the network are coated with a low modulus elastomeric material. U.S. Pat. Nos. 5,552,208 and 5,587,230 disclose an article and method for making an article comprising at least one network of high strength fibers and a matrix composition that includes a vinyl ester and diallyl phthalate. U.S. Pat. No. 6,642,159 discloses an impact resistant rigid composite having a plurality of fibrous layers which comprise a network of filaments disposed in a matrix, with elastomeric layers there between. The composite is bonded to a hard plate to increase protection against armor piercing projectiles.
Hybrid ballistic resistant structures, in and of themselves, are known. For example, U.S. Pat. Nos. 5,179,244 and 5,180,880 teach soft or hard body armor utilizing a plurality of plies made from dissimilar ballistic materials, joining aramid and non-aramid fiber plies into a combined structure and utilizing polymeric matrix materials that deteriorate when exposed to liquids. U.S. Pat. No. 5,926,842 also describes hybridized ballistic resistant structures utilizing polymeric matrix materials that deteriorate when exposed to liquids. Further, U.S. patent U.S. Pat. No. 6,119,575 teaches a hybrid structure containing a first section of aromatic fibers, a second section of a woven plastic and a third section of polyolefin fibers.
Currently, flexible body armor articles do not provide suitable protection against high energy ballistic threats, such as bullets and high energy fragments. Additionally, while hard armor articles do offer sufficient protection against high energy threats, they are not suitable for flexible vest applications. To solve this problem, the present invention provides a hybrid structure that incorporates the benefits of dissimilar materials and offers excellent ballistic protection at a light weight. Particularly, the invention provides hybrid ballistic resistant structures incorporating both flexible and semi-rigid components.